If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Not surprising that there is evidence of past volcanic activity on Mercury given the planet's proximity to the most massive object in the solar system. The sun's tidal forces probably keep Mercury's interior churning. Jupiter causes similar events on its moons, especially Io.

---

Did you guys see the Martian rock that looks like a person with arms outstretched? The photo was taken by the NASA Spirit explorer and was widely reported on cable news channels last week.

Simple one; when I wake in the morning, right as I open my front door I've seen the two planets next to each other, staring right back at me. I heard its Venus and Mercury, I think. Only a few more days left, before it's gone for several years!

"I went to Star Wars Celebration VII in Anaheim, and I didn't get even a lousy t-shirt."

Yes! I've been greeted with that sight every morning, too, BCJ! It is indeed Mercury and Venus. Seems our little planet appears to be in some sort of alignment with them these days. When I look to the sky, I'm hoping to see a big, black monolith float into the alignment, too.....

Did you guys see the Martian rock that looks like a person with arms outstretched? The photo was taken by the NASA Spirit explorer and was widely reported on cable news channels last week.

I thought it was a funny picture 'cos it looked like the "figure" pushed another one off the rock and the other one was laying unconscious on the ground!!!

Originally Posted by Bel-Cam Jos

Simple one; when I wake in the morning, right as I open my front door I've seen the two planets next to each other, staring right back at me. I heard its Venus and Mercury, I think. Only a few more days left, before it's gone for several years!

I think it's really romantic (and not in a lovey dovey kinda way) to look up at the sky and see these celestial bodies up there and think about the passing of time and how fortunate we are to see and appreciate these occurrences.

Not surprising that there is evidence of past volcanic activity on Mercury given the planet's proximity to the most massive object in the solar system. The sun's tidal forces probably keep Mercury's interior churning. Jupiter causes similar events on its moons, especially Io.

Tidal forces really aren't at play with Mercury, at least as far as volcanism goes. Io is in the middle of three way tug-of-war between Jupiter, Europa, and Ganymede. Venus and the Earth (the closest bodies to Mercury) as simply too far away for such interaction. I think comparison to Ganymede is more fair. Mars, Venus, and the Moon all show evidence of past volcanism. I think anytime you have a liquid core in a rocky planetary body over a geological time scales you'll see volcanism. My guess is the minor planets will also show evidence of past volcanic activity.

Now that's not to say at tidal forces aren't affecting Mercury. The planet has a global magnetic field. It's thought it's generated in a similar manner to the Earth's. Something must be keeping Mercury's core soft. Tidal interactions are the simplest explanation. If Venus were closer or more massive you might see a planet like Io. So the core is soft enough to keep the B-field, but not enough for active volcanoes. Like Ganymede.

"I'm sick and tried of these motherfrakkking Sith on this motherfrakkker plane!"
Mace Windu - Episode 2.5: Sith on a Plane